Used properly, sunscreens with an SPF of 8 or higher completely block UVB radiation and prevent synthesis of vitamin d.
使用得当的防晒系数为8或更高的防晒霜在完全阻挡紫外线辐射的同时也阻止了维生素d的合成。
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That's a problem, particularly when it comes to vitamin D. Federal guidelines recommend that children get 400 I.U. of the vitamin a day, equivalent to four 8 oz. glasses of milk.
I also worked on movie clip playback and on a dedicated color-corrector to translate Cineon images to 8 bit, this is what led me to concentrate on images rather than 3-d.